Strip control codes and extended characters from a string

var str = "\ba\x00b\n\rc\fd\xc3\x7ffoo"

var letters = str.chars.map{.ord}
say letters.map{.chr}.join.dump

var nocontrols = letters.grep{ (_ > 32) && (_ != 127) }
say nocontrols.map{.chr}.join.dump

var noextended = nocontrols.grep{ _ < 127 }
say noextended.map{.chr}.join.dump

Output:

"\ba\0b\n\rc\fd\xC3\x7Ffoo"
"abcd\xC3foo"
"abcdfoo"